FFBitrateViewer is a FFProbe GUI that purpose is to visualize frames` bitrate extracted by FFProbe. It is inspired by Bitrate Viewer (link to Web Archive as the program's web-site and forum are long dead). FFBitrateViewer allows you to select multiple files without dealing with command line and get “per frame” or “per second” info for all of them in one go.

Plots a graph showing the variation of the bitrate as well as up to 75 I-Frames throughout your video. The average bitrate is shown on the legend. In addition to this, the minimum, maximum and standard deviation is shown above the graph. See the example below: